Optimization of channel dimensions and gas diffusion layer thickness based on mass transfer characteristics of proton exchange membrane fuel cell

Abstract

To improve the volume power density of proton exchange membrane fuel cell (PEMFC), a design of graphite bipolar plate straight channel characterized by narrow ribs is studied in this article. A three-dimensional multiphase model of PEMFC is employed to analyze the effects of the geometric parameters on the mass transfer characteristics and power density. The results show that smaller channel width and channel depth can enhance water removal and gas transport, which could increase the fuel cell performance. However, the influence of gas diffusion layer (GDL) thickness on fuel cell performance is not monotonous which means that there is an optimal value. The overall dimensions are optimized with volume power density as objective function. The best performance is obtained when the channel width, channel depth and GDL thickness are 0.1, 0.2 and 0.05 mm, respectively. Compared with the conventional channel design, the volume power density of optimal channel is significantly increased by 211.32% at 0.6 V.